* Q2 core profit rose 9 pct to 5.94 bln v 5.76 bln consensus
* Revs increase 6.0 pct to 18.89 bln euros, powered by U.S.
* Modestly raises full-year core profit target to 22.3 bln
* Telekom shares hinge on prospects for U.S. merger tie-up (Adds U.S. merger speculation, stock, analyst comments)
FRANKFURT, Aug 3 (Reuters) - Deutsche Telekom, Europe's biggest telecom company, on Thursday posted quarterly results that topped expectations, with a 9 percent rise in core profit powered by strength in the United States and modest gains in Germany and Europe.
The German company slightly nudged up its 2017 outlook for core profit to around 22.3 billion euros ($26.4 billion) from 22.2 billion euros previously.
Second-quarter results were driven by the contribution from its T-Mobile US business, 64-percent controlled by Deutsche Telekom, which last month said it added more than a million customers for the 17th quarter in a row.
T-Mobile, the No. 3 U.S. mobile operator, is one of two public suitors seeking a tie-up with No. 4-ranked Sprint Corp in what would mark a mega-merger deal that could reshape the U.S. telecommunications market into three huge players.
Reuters reported this week that Sprint's majority owner, Japan's SoftBank Group is exploring merger options not just with T-Mobile but also a tie-up with cable communications provider Charter Communications.
Deutsche Telekom's stock has seesawed on the prospects for its T-Mobile business reaching a merger deal with Sprint, gaining as much as 12 percent in May when speculation peaked but falling to trade down 4.4 percent in the year to date as no deal arose.
The shares were up 1.6 percent at 15.78 euros by 0718 GMT on Thursday, making them the biggest gainers on Germany's blue-chip DAX index, which was down 0.3 percent.
"The stock is all about Sprint," brokerage Bernstein said, noting the quarterly financial results followed a consistent pattern of increasing strength, led by the U.S. business.
Overall at Deutsche Telekom, adjusted earnings before interest, tax, depreciation and amortisation (EBITDA), excluding special items, rose 8.9 percent to 5.94 billion euros, beating forecasts, which ranged from 5.63 billion to 5.89 billion euros in a Reuters poll.
Revenue rose by 6.0 percent to 18.89 billion euros, topping the high end of forecasts by 10 analysts polled by Reuters.
Citi analyst Simon Weeden called the results a solid set of figures with an "unexpected recovery" in revenue growth for Deutsche Telekom's German mobile services business, which turned slightly positive in the quarter, aided by a big marketing push.
Telekom said it invested 3 billion euros in capital spending, a 12.4 percent increase, leading quarterly free cash flow to dip 1.4 percent to 1.3 billion euros. For the full year, it reaffirmed its annual free cash flow target of 5.5 billion.
During the second quarter, the United States business contributed half of Telekom group revenue and 44 percent of core profit, while Germany contributed one-third of reported profits and other business roughly one-fifth.
T-Systems, its technical and communications consulting business, posted a 1.8 percent decline in second-quarter revenue amid sustained industry pricing pressure, Telekom said. Orders in the second quarter dropped 13.4 percent to 1.3 billion euros.
($1 = 0.8440 euros) (Reporting By Eric Auchard; Editing by Maria Sheahan and Susan Thomas)